Hi Everyone

Oz18650

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Oct 2, 2017
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Hi Everyone!

I have been lurking here a while, but decided it is time for me to start partiicipating.

I have learned a lot from Pete's videos as well as AverageJoe and Nerdville. Thank you very much to each of you for the fantastic videos!

I have just started my own 18650 adventure with 2 battery packs opened.
One pack had 2 cells and one had 8.

I am planning on starting out small witha few USB powerbanks.

The 2 cells were charged before the pack was dismantled, and they seem to be holding charge, but the 8 cells are close to zero volts.

So far I have bought a few 18650 cell holders, some TP4056 modules and some zb2l3 for capacity testing and a few empty usb powerbanks (2,4 and 6 cell) for 18650 cells.

I am not sure what next after the USB power banks. Maybe an ebike conversion.

I like the idea of a decent size powerwall or possibly even an EV car, but have to see how things go.

My young daughter is very excited about the idea of participating in recycling and that is what made me take the step from thinking "That is an interesting idea" to "I am going to give it a go".

She got hold of the multimeter today and checked the voltages of each of the cells.

Thanks to those who have put this community together and everyone who participates here.

James.
 

hbpowerwall

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Welcome!
 

daromer

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Welcome!

Perhaps convert some toys to 18650 based ones? Just beware of and handle the safety concerns when dealing with 2nd hand cells in such devices and keep up the work!
 

Oz18650

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DarkRaven said:
Welcome!

I wish both of you lots of fun on the way :)

Thank you!

Thank you Pete too! (not sure why your quote is not here)....

daromer said:
Welcome!

Perhaps convert some toys to 18650 based ones? Just beware of and handle the safety concerns when dealing with 2nd hand cells in such devices and keep up the work!

Hmm. We dont really have many battery powered toys.

My youngest daughter (4th grade) would probably get much more of a kick out of something like "running the fridge from batterys charged from solar panels" than from any type of toys. Maybe this will be a first attempt at a powerwall type thing? Possibly the load from the fridge is a lot to start with? Maybe I will start with the light on our aquarium?
She would probably like an 18650 powered night light for her room too.
I'll have to ask her to come up with some ideas.

She wants to have a business which helps the environment. She sat down with 2 other friends at school to do a business plan after my wife told her a business needs a business plan.
They decided on a business name, that the business is about "we recycle everything" and they wrote a long list of possible products. I was pretty impressed with what they came up with considering they dont know what a business plan really is.
It was seeing her page full of work that made me decide to show her what I could with the laptop cells.

The 18650 holders arrived in the mail today, and she was really excited. She asked about the "little square things for charging" (tp4056) and when they would arrive.

I put one of the charged cellls into one of the holders and showed her the tiny sparks that happen when the wires are shorted. I asked her "What do you think the sparks can do?" and she said "Start a fire".
I explained that she cannot do anything without asking, and me supervising.

I suspect my older daughterwill be less enthusiastic, but will be interested and learn plenty too.
 

daromer

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Ahh! :)

If its an older fridge that one will take alot of umph to start and its not something you start up with just a few cells. Everything with motors need to considered to take atleast 5 times or more during startup unless you know otherwise.

best is to start with lamps. For instance night-lamps is perfect! Charged during day and used during night!
 

howiegrapek

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Sep 25, 2017
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Oz18650 said:
DarkRaven said:
Welcome!

I wish both of you lots of fun on the way :)

Thank you!

Thank you Pete too! (not sure why your quote is not here)....

daromer said:
Welcome!

Perhaps convert some toys to 18650 based ones? Just beware of and handle the safety concerns when dealing with 2nd hand cells in such devices and keep up the work!

Hmm. We dont really have many battery powered toys.

My youngest daughter (yr 4) would probably get much more of a kick out of something like "running the fridge from batterys charged from solar panels" than from any type of toys. Maybe this will be a first attempt at a powerwall type thing? Possibly the load from the fridge is a lot to start with? Maybe I will start with the light on our aquarium?
She would probably like an 18650 powered night light for her room too.
I'll have to ask her to come up with some ideas.

She wants to have a business which helps the environment. She sat down with 2 other friends at school to do a business plan after my wife told her a business needs a business plan.
They decided on a business name, that the business is about "we recycle everything" and they wrote a long list of possible products. I was pretty impressed with what they came up with considering they dont know what a business plan really is.
It was seeing her page full of work that made me decide to show her what I could with the laptop cells.

The 18650 holders arrived in the mail today, and she was really excited. She asked about the "little square things for charging" (tp4056) and when they would arrive.

I put one of the charge cellls into one of the holders and showed her the tiny sparks that happen when the wires are shorted. I asked her "What do you think the sparks can do?" and she said "Start a fire".
I explained that she cannot do anything without asking, and me supervising.

I suspect my older daughterwill be less enthusiastic, but will be interested and learn plenty too.

Welcome - it sounds like your little one has a great head on her shoulders - the key to our planet's future is all about our kids! I love that you are getting her involved and enthusiastic early.
 

Oz18650

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daromer said:
Ahh! :)

If its an older fridge that one will take alot of umph to start and its not something you start up with just a few cells. Everything with motors need to considered to take atleast 5 times or more during startup unless you know otherwise.

best is to start with lamps. For instance night-lamps is perfect! Charged during day and used during night!

re the fridge, I was thinking it would be at the "big, but not quite whole house/grid tied" end of the size of possible projects.

Thanks all, for the words of encouragement!
 

Oz18650

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Its been quite a while, but it is time for an update.
Since I started extracting cells, I made a few USB powerbanks, but I was having quite a few sanyo heaters, a few zero volt packs and not able to source a lot of packs to open, so things were very slow.
However, recently I found a good source of 18650 cells!
Things are looking good for getting a decent size powerwall project going!
 

Oz18650

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Another update.

So far I have extracted over 550 cells and I am hoping that the majority of the cells will be good.
Only a very small number have had low voltage. The vast majority are between 3.6 and 4 volts.
I have not sorted out what my test process will be yet.
I have a few hw586 (similar to zb2l3) testers, but over the last few days I have done some repeated testing of 1 cell, with the same charger and capacity tester and the results seem a bit inconsistent.
 

DarkRaven

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Within certain limits it has to be expected that the results are inconsistent, especially with these cheap testers. If the differences aren't too big then it's not a big deal.
 

DCkiwi

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Oz18650 said:
Another update.

So far I have extracted over 550 cells and I am hoping that the majority of the cells will be good.
Only a very small number have had low voltage. The vast majority are between 3.6 and 4 volts.
I have not sorted out what my test process will be yet.
I have a few hw586 (similar to zb2l3) testers, but over the last few days I have done some repeated testing of 1 cell, with the same charger and capacity tester and the results seem a bit inconsistent.

yahoo! you have a source (of cells) -- that is fantastic news. took me months to find, too.

I don't worry about low initial voltages. Other than having to pre-charge them VERY slowly (and I mean very slowly ~10-20mA) ... I find most test out well, capacity wise (I dont care about, or test for IR).

My test process involves (in brief) a super slow pre-charge (as needed), wait for a week (ish) to check for selfdischarge, then I triple test each cell (pair..) for capacity, then level them all to a storage charge of ~3.92V. When I need to build, I select some roughly matching cells, check them again for self discharge, re-level to 3.92V, and get busy with soldering iron.

I test with 'cheap' testers (Opus BT-3100 v2.2) and they can be a bit off, as DarkRaven noted, BUT ...

Most cells test out all three times with exactly the same capacity results. IE within 0.5% (!). And some cells test less each time ... circling downwards rapidly -- this is partly why I triple test -- so I 'discard' them no matter what their capacity. And yet some others rise each test (just a little, not much) ... and a very few test out like a regular yo-yo, IE all over the place. I dont much like those either. Im not entirely sure what makes them do this, but ... this is my experience. The main thing for me is that my testers are all calibrated the same as each other, and therefore it doesnt matter which tester I use, so the capacity results are similar between them. Best of luck developing your own style/methodology. I do not believe there is any one 'perfect' method, its a very personal choice etc.

I would be interested in whether you have similar results with a larger sample than one cell. IE is it your tester/s, OR is it that particular cell?
 

Wolf

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DCkiwi said:
I don't worry about low initial voltages. Other than having to pre-charge them VERY slowly (and I mean very slowly ~10-20mA) ... I find most test out well, capacity wise (I dont care about, or test for IR).
DCkiwi,

I don't worry about low voltage either and do a slow charge as you. But the IR thing well I guess everyone is entitled to their opinion.
I personally feel that it is important to the degree that I can determine the health of a battery with a simple IR test. I mean the manufacturer has given us in their spec sheets (not all of them) their recommended IR state of the battery at 1kH AC. To me when a manufacturer recommends a measurement to be taken and gives a specific value within certain tolerances it means something to me. Kinda like torquing the head bolts on an engine. You don't just make them tight because tight can mean a lot of different things to different people hence there is a "standard" be it Nm or ft-lb. So I kinda think IR has a place in this mysterious world of 18650 and Li ion and the manufacturer has given us a standard "1kH AC 4 wire Kelvin".

Wolf
 

DCkiwi

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Wolf said:
[...]
the IR thing well I guess everyone is entitled to their opinion.
I personally feel that it is important to the degree that I can determine the health of a battery with a simple IR test. I mean the manufacturer has given us in their spec sheets (not all of them) their recommended IR state of the battery at 1kH AC. To me when a manufacturer recommends a measurement to be taken and gives a specific value within certain tolerances it means something to me. Kinda like torquing the head bolts on an engine. You don't just make them tight because tight can mean a lot of different things to different people hence there is a "standard" be it Nm or ft-lb. So I kinda think IR has a place in this mysterious world of 18650 and Li ion and the manufacturer has given us a standard "1kH AC 4 wire Kelvin".

I *do* think IR is important, in terms of what you said (above). BUT there is ZERO importance to ME, so I dont pay attention (irrelevent) or test for it (waste of my time). Heres why: 1/ many (most?) of my cells are used in big batteries with LOW discharge setups -- think C100 (IE <20mA) 2/ the used laptop cells I process here in NZ are almost ALL high IR. 3/ my motivation is to actually USE these recovered cells, thrashing them to death, NOT to just immediately return them to the landfill from which they were rescued. 4/ I am a cartridge style fanbois. this makes swapping out dead cells much less stressful than if they were all buried in 80s packs etc. 5/ IR is 'tested' implicitly by the triple capacity test. if they survive that ok, then their IR is ok for me.

When I need super low IR (EG 4WD electric skateboard), I use cells from powertools. If I needed reliable cells I would not choose recovered cells, I would buy the latest chemistry, brand NEW. and how does the saying go? ... 'the best [cell] is the one that youve got' ...

apols for any confusion here. wasnt wanting to start another IR discussion, more made the comment in passing, and in relation to previous post of inconsistent capacity test results.

EDIT: @Oz18650: If you back off the discharge/test current, do the capacity test results become more consistent? If so, this would indicate to me that you have an IR issue (almost dead) ... if not, then I say they might be End Of Life (dead) ...
 

Oz18650

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DCkiwi said:
EDIT: @Oz18650: If you back off the discharge/test current, do the capacity test results become more consistent? If so, this would indicate to me that you have an IR issue (almost dead) ... if not, then I say they might be End Of Life (dead) ...

The test I did was with only 1 of the 2 supplied resistors as I was wanting the test to be "easy" on the cell and hoping it would be more consistent that way with a smaller voltage drop due to the load.

I have purchased some zb206 testers, which should do IR testing however I have not seem much about how accurate these are for IR.
I have also purchased a yr1030 IR tester, as recommended by another very helpful member here.

I have extracted over 1000 cells now, so I am really keen for the test equipment to arrive, so I can start on testing.

I think I have a good grasp of the pack design part of this project, but need to find out more about other parts of system design.
 

DCkiwi

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Oz18650 said:
[...]

I have extracted over 1000 cells now, so I am really keen for the test equipment to arrive, so I can start on testing.

I think I have a good grasp of the pack design part of this project, but need to find out more about other parts of system design.

Nice update ... : )

While you are waiting for the test equip to arrive, may I suggest something to take all your time until then?

pre/charge all your cells ... let them sit for a week (or two, no longer) at 4.20V (assuming you using LiIon-Co chemistry). then test for selfdischarge.

I generally find that any that go below 4.10V are junk, and I am suspicious of any that drop below 4.16V in this relatively brief time. this can be a mind numbing task, but takes some time, depending on your charging/lab setup. you might be able to weed out 50+ cells that self discharge, and use slots in testers for viable cells only.

then you could even start on 'flattening' these failed cells, ready for final disposal ... all before testing equip arrives. fun fun!
 

Oz18650

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Thanks DCkiwi.
The ZB206s arrived yesterday! However i am still waiting on the yr1030 for IR testing
I have started some testing of thr zb206s to verify that I am happy with using them.
First cycle with a cell looked reasonable. Now to see how repeatable testing is.
I also have an idea for testing the tester which might be good to verify accuracy. I will try it out and report back here.
The steps you suggest before testing starts could be good, however I want to measure and record voltage and IR of the cells before charging and testing, so I will wait for the IR tester to arrive for testing to really get underway.
 

Oz18650

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Thanks 0yx26.

I have extracted over 1300 cells now.

Still have a several hundred to go, before getting more cells.

I am thinking of aiming for roughly 14s 100p for about 10kwh, so depending on how my testing goes, I might get close to that.

I am hoping to get some zb206s set up with power and cell holders this weekend.

I might have to start a build thread.
 
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